{"apiVersion":"1.0","identifier":"CVE-2026-80633","description":"In the Linux kernel, the following vulnerability has been resolved: iommufd: Take dma_resv lock before dma_buf_unpin() in release path dma_buf_unpin() requires the caller to hold the exporter-s dma_resv lock: void dma_buf_unpin(struct dma_buf_attachment *attach) { ... dma_resv_assert_held(dmabuf->resv); ... } iopt_release_pages() calls dma_buf_unpin() without taking that lock, so every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases the last reference on a DMABUF-backed iopt_pages triggers a WARN. This was hit while running tools/testing/selftests/iommu/iommufd: WARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70 RIP: 0010:dma_buf_unpin+0x62/0x70 Call Trace: <TASK> dma_buf_unpin+0x62/0x70 iopt_release_pages+0xe4/0x190 iopt_unmap_iova_range+0x1c7/0x290 iopt_unmap_all+0x1a/0x30 iommufd_ioas_destroy+0x1d/0x50 iommufd_fops_release+0x93/0x150 __fput+0xfc/0x2c0 __x64_sys_close+0x3d/0x80 do_syscall_64+0x65/0x180 </TASK> Take the dma_resv lock around dma_buf_unpin() in iopt_release_pages(), matching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the reservation lock internally, so it must remain outside the locked region.","publishedAt":"2026-08-28T08:16:48","lastModifiedAt":"2026-08-28T08:16:48","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80633","cvssScore":null,"cvssVector":"Pending","epssProbability":0.00155,"riskScore":0,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-80633","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-80633","en":"https://www.redsauce.net/en/cves/CVE-2026-80633","fr":"https://www.redsauce.net/fr/cves/CVE-2026-80633","pt":"https://www.redsauce.net/pt/cves/CVE-2026-80633","de":"https://www.redsauce.net/de/cves/CVE-2026-80633","sk":"https://www.redsauce.net/sk/cves/CVE-2026-80633","el":"https://www.redsauce.net/el/cves/CVE-2026-80633"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-80633"}}